Field of the Invention
Embodiments of the invention relate to a solar cell module, and more particularly to a solar cell module including interdigitated back contact solar cells.
Description of the Related Art
Recently, as existing energy sources such as petroleum and coal are expected to be depleted, interests in alternative energy sources for replacing the existing energy sources are increasing. Among the alternative energy sources, solar cells for generating electric energy from solar energy have been particularly spotlighted.
A solar cell generally includes a substrate and an emitter region, which are formed of semiconductors of different conductive types, for example, a p-type and an n-type, and electrodes respectively connected to the substrate and the emitter region. A p-n junction is formed at an interface between the substrate and the emitter region.
When light is incident on the solar cell, electrons inside the semiconductor become free electrons (hereinafter referred to as “electrons”) by the photoelectric effect. Further, electrons and holes respectively move to an n-type semiconductor (for example, the emitter layer) and a p-type semiconductor (for example, the substrate) based on a principle of the p-n junction. Then, the electrons and the holes are collected by the electrodes electrically connected to the emitter region and the substrate.
In recent times, an interdigitated back contact solar cell has been developed to increase a light receiving area and the efficiency of the solar cell by forming an electron current collector and a hole current collector on a back surface of the substrate (i.e., the back surface on which light is not incident).